itest: extract and tune proof courier backoff config

With this commit we optimize the backoff config to enable much faster
proof transmission during integration tests.
A significant speedup also comes from reducing the time the custodian
waits between detecting a transfer on-chain and attempting to fetch the
proof with the courier.

Author: guggero

itest/tapd_harness.go

@@ -46,6 +46,20 @@ var (
 		tapdb.DefaultPostgresFixtureLifetime, "The amount of time to "+
 			"allow the postgres fixture to run in total. Needs "+
 			"to be increased for long-running tests.")
+
+	// defaultBackoffConfig is the default backoff config we'll use for
+	// sending proofs.
+	defaultBackoffConfig = proof.BackoffCfg{
+		BackoffResetWait: time.Second,
+		NumTries:         5,
+		InitialBackoff:   300 * time.Millisecond,
+		MaxBackoff:       600 * time.Millisecond,
+	}
+
+	// defaultProofRetrievalDelay is the default delay we'll use for the
+	// custodian to wait from observing a transaction on-chan to retrieving
+	// the proof from the courier.
+	defaultProofRetrievalDelay = 200 * time.Millisecond
 )
 
 const (
@@ -182,14 +196,9 @@ func newTapdHarness(t *testing.T, ht *harnessTest, cfg tapdConfig,
 	// Populate proof courier specific config fields.
 	//
 	// Use passed in backoff config or default config.
-	backoffCfg := &proof.BackoffCfg{
-		BackoffResetWait: 2 * time.Second,
-		NumTries:         3,
-		InitialBackoff:   2 * time.Second,
-		MaxBackoff:       2 * time.Second,
-	}
+	backoffCfg := defaultBackoffConfig
 	if opts.proofSendBackoffCfg != nil {
-		backoffCfg = opts.proofSendBackoffCfg
+		backoffCfg = *opts.proofSendBackoffCfg
 	}
 
 	// Used passed in proof receiver ack timeout or default.
@@ -203,7 +212,7 @@ func newTapdHarness(t *testing.T, ht *harnessTest, cfg tapdConfig,
 	// config from the hashmail courier config.
 	finalCfg.HashMailCourier = &proof.HashMailCourierCfg{
 		ReceiverAckTimeout: receiverAckTimeout,
-		BackoffCfg:         backoffCfg,
+		BackoffCfg:         &backoffCfg,
 	}
 
 	switch typedProofCourier := (opts.proofCourier).(type) {
@@ -224,7 +233,11 @@ func newTapdHarness(t *testing.T, ht *harnessTest, cfg tapdConfig,
 		finalCfg.HashMailCourier = nil
 	}
 
+	ht.t.Logf("Using proof courier address: %v",
+		finalCfg.DefaultProofCourierAddr)
+
 	// Set the custodian proof retrieval delay if it was specified.
+	finalCfg.CustodianProofRetrievalDelay = defaultProofRetrievalDelay
 	if opts.custodianProofRetrievalDelay != nil {
 		finalCfg.CustodianProofRetrievalDelay = *opts.custodianProofRetrievalDelay
 	}